1. Field of the Invention
The present embodiments relate to a method of supporting a Single Cell Point-to-Multipoint (SC-PTM) for an narrow band Internet of Thing (NB-IoT) terminal defined in a third generation group project partnership (3GPP) long term evolution (LTE)/LTE-Advanced system.
2. Description of the Prior Art
In 3GPP Release-12/13, a Bandwidth Reduced Low complexity (BL) terminal technology and a Coverage Enhancement (CE) terminal technology have been standardized. A Low Complexity (LC) terminal represents a terminal targeting low-end application having a low profit, a low speed, and a low latency sensitivity, such as some Machine Type Communication (MTC) terminals. The LC terminal has reduced Tx and Rx capabilities compared to terminals of other categories. A BL terminal operates in an LTE system band having a limited channel bandwidth of 6 PRB corresponding to a maximum channel bandwidth available in a 1.4 MHz LTE system. A CE terminal needs an enhanced coverage function to connect to a cell.
In 3GPP Release-13, Narrowband Internet of Things (NB-IoT) technology has been standardized. The aspect thereof is to specify a wireless access for cellular IoT, and includes improved indoor coverage, support for large-scale low-speed terminals, low latency sensitivity, very low cost of terminals, low power consumption, and optimized network architecture.
In Release-13, a BL/CE terminal or an NB-IoT terminal has been provided with functions for enabling the 3GPP system to rapidly penetrate into a low-cost IoT market. Accordingly, some functions provided to a typical LTE terminal that provides a mobile broadband service are not provided to the BL/CE terminal or the NB-IoT terminal.
For example, multicast transmission (an MBMS service or SC-PTM transmission) provided to a typical LTE terminal is not provided to a Release-13 BL/CE terminal or a Release-13 NB-IoT terminal. Therefore, there is no method defined for supporting multicast transmission of a BL/CE terminal or an NB-IoT terminal in Release-13.